我在代码中设置了一个表“ address_layer”。在这里,我试图总结“ Anzahl”一栏。 问题在于,如果值是Empty(其中什么也没有),则代码会中断。
polygon_layer = arcpy.GetParameterAsText(0)
address_layer = arcpy.GetParameterAsText(1)
selected_oids = []
with arcpy.da.SearchCursor(polygon_layer, "OID@") as cursor:
for row in cursor:
selected_oids.append(row[0])
workspace = arcpy.Describe(polygon_layer).path
anzahl_total = 0
try:
edit = arcpy.da.Editor(workspace)
edit.startEditing(False, True)
for oid in selected_oids:
arcpy.SelectLayerByAttribute_management(polygon_layer, "NEW_SELECTION", "OBJECTID = {0}".format(oid))
arcpy.SelectLayerByLocation_management(address_layer, "WITHIN", polygon_layer)
#address_count_within = int(arcpy.GetCount_management(address_layer).getOutput(0))
#arcpy.AddMessage('Number of address points within Polygon (OBJECTID={0}): {1}'.format(oid, address_count_within))
with arcpy.da.SearchCursor(address_layer, "Anzahl") as cursor:
for row in cursor:
anzahl_total = anzahl_total + row[0]
#print anzahl_total
#edit.startOperation()
with arcpy.da.UpdateCursor(polygon_layer, ["anzahl"]) as cursor:
for row in cursor:
row[0] = anzahl_total
cursor.updateRow(row)
#edit.stopOperation()
edit.stopEditing(True)
finally:
pass
如何将空值设置为“ 0”,以便对此求和? 在此部分中断
with arcpy.da.SearchCursor(address_layer, "Anzahl") as cursor:
for row in cursor:
anzahl_total = anzahl_total + row[0]
此错误出现:
line 29, in <module>
anzahl_total = anzahl_total + row[0]
TypeError: unsupported operand type(s) for +: 'int' and 'NoneType'
答案 0 :(得分:2)
要检查行是否为空,您可以像这样test for it:
with arcpy.da.SearchCursor(address_layer, "Anzahl") as cursor:
for row in cursor:
if row[0] is not None:
anzahl_total += row[0]
您还可以将generator expression与sum()
一起使用,例如:
with arcpy.da.SearchCursor(address_layer, "Anzahl") as cursor:
anzahl_total += sum(row[0] for row in cursor if row[0] is not None)